// CodeMirror, copyright (c) by Marijn Haverbeke and others
// Distributed under an MIT license: https://codemirror.net/LICENSE

(function(mod) {
    if (typeof exports == "object" && typeof module == "object") // CommonJS
        mod(require("../../lib/codemirror"));
    else if (typeof define == "function" && define.amd) // AMD
        define(["../../lib/codemirror"], mod);
    else // Plain browser env
        mod(CodeMirror);
})(function(CodeMirror) {
    "use strict";

    CodeMirror.registerHelper("fold", "brace", function(cm, start) {
        var line = start.line, lineText = cm.getLine(line);
        var tokenType;

        function findOpening(openCh) {
            for (var at = start.ch, pass = 0;;) {
                var found = at <= 0 ? -1 : lineText.lastIndexOf(openCh, at - 1);
                if (found == -1) {
                    if (pass == 1) break;
                    pass = 1;
                    at = lineText.length;
                    continue;
                }
                if (pass == 1 && found < start.ch) break;
                tokenType = cm.getTokenTypeAt(CodeMirror.Pos(line, found + 1));
                if (!/^(comment|string)/.test(tokenType)) return found + 1;
                at = found - 1;
            }
        }

        var startToken = "{", endToken = "}", startCh = findOpening("{");
        if (startCh == null) {
            startToken = "[", endToken = "]";
            startCh = findOpening("[");
        }

        if (startCh == null) return;
        var count = 1, lastLine = cm.lastLine(), end, endCh;
        outer: for (var i = line; i <= lastLine; ++i) {
            var text = cm.getLine(i), pos = i == line ? startCh : 0;
            for (;;) {
                var nextOpen = text.indexOf(startToken, pos), nextClose = text.indexOf(endToken, pos);
                if (nextOpen < 0) nextOpen = text.length;
                if (nextClose < 0) nextClose = text.length;
                pos = Math.min(nextOpen, nextClose);
                if (pos == text.length) break;
                if (cm.getTokenTypeAt(CodeMirror.Pos(i, pos + 1)) == tokenType) {
                    if (pos == nextOpen) ++count;
                    else if (!--count) { end = i; endCh = pos; break outer; }
                }
                ++pos;
            }
        }
        if (end == null || line == end && endCh == startCh) return;
        return {from: CodeMirror.Pos(line, startCh),
            to: CodeMirror.Pos(end, endCh)};
    });

    CodeMirror.registerHelper("fold", "import", function(cm, start) {
        function hasImport(line) {
            if (line < cm.firstLine() || line > cm.lastLine()) return null;
            var start = cm.getTokenAt(CodeMirror.Pos(line, 1));
            if (!/\S/.test(start.string)) start = cm.getTokenAt(CodeMirror.Pos(line, start.end + 1));
            if (start.type != "keyword" || start.string != "import") return null;
            // Now find closing semicolon, return its position
            for (var i = line, e = Math.min(cm.lastLine(), line + 10); i <= e; ++i) {
                var text = cm.getLine(i), semi = text.indexOf(";");
                if (semi != -1) return {startCh: start.end, end: CodeMirror.Pos(i, semi)};
            }
        }

        var startLine = start.line, has = hasImport(startLine), prev;
        if (!has || hasImport(startLine - 1) || ((prev = hasImport(startLine - 2)) && prev.end.line == startLine - 1))
            return null;
        for (var end = has.end;;) {
            var next = hasImport(end.line + 1);
            if (next == null) break;
            end = next.end;
        }
        return {from: cm.clipPos(CodeMirror.Pos(startLine, has.startCh + 1)), to: end};
    });

    CodeMirror.registerHelper("fold", "include", function(cm, start) {
        function hasInclude(line) {
            if (line < cm.firstLine() || line > cm.lastLine()) return null;
            var start = cm.getTokenAt(CodeMirror.Pos(line, 1));
            if (!/\S/.test(start.string)) start = cm.getTokenAt(CodeMirror.Pos(line, start.end + 1));
            if (start.type == "meta" && start.string.slice(0, 8) == "#include") return start.start + 8;
        }

        var startLine = start.line, has = hasInclude(startLine);
        if (has == null || hasInclude(startLine - 1) != null) return null;
        for (var end = startLine;;) {
            var next = hasInclude(end + 1);
            if (next == null) break;
            ++end;
        }
        return {from: CodeMirror.Pos(startLine, has + 1),
            to: cm.clipPos(CodeMirror.Pos(end))};
    });

});
